无粘结柔性管抗拉伸层结构分析

柔性管抗拉伸层是复杂的空间螺旋线结构,其结构响应分析对柔性管疲劳分析、强度分析和屈曲分析有重要作用。文章基于曲梁理论,应用斜驶螺旋线假设和测地线假设两种空间曲线公式,以空间细长杆理论及胡克定律本构方程为基础,采用格林应变张量与第二Kirchoff应力张量度量,对深海无粘结柔性管抗拉伸层螺旋形钢缆结构平衡方程进行了推导,编写了分析程序。利用该程序,分析了抗拉伸层钢缆在轴对称载荷下和弯矩作用下的曲率变化和结构响应;同时利用三维直梁有限元模型与曲梁有限元模型建立数值模型,将程序结果与数值模拟模型结果进行了对比,证明了结果可行性。该结果可为柔性管抗拉伸层结构设计提供快速的预估计方法。

Analysis of tensile armor layer structural behaviors in flexible pipe

Tensile armor layers of flexible pipe are complex helix structures, whose stress analyses are sig-nificant to flexible pipe’s fatigue, strength and buckling behaviors. This paper is based on curved beam theory. Equilibrium equations of tensile armor wires in deepwater unbonded flexible pipe were solved with assumptions of loxodromic curve and geodesic curve, based on slender rod theory and elastic constitutive relationship. The curvatures and structural response under axisymmetric load and bend moment were ana-lyzed. A three dimensions beam finite element model and a three dimensions curved beam element model were built by FEM software to compare with the results. The results show that the formulations and codes are reasonable for predicting structural responses of tensile armor wires. This solution provides a fast method to evaluate the stress and curvatures in design of flexible pipe’s preliminary design.